[heap] Fix atomicity of IncrementalMarking::TransferColor.

Bug: chromium:694255
TBR: mlippautz@chromium.org
Change-Id: Ie9f2f7bff8ada297b1d078947f073eaf62ac0649
Reviewed-on: https://chromium-review.googlesource.com/610782Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47293}

src/heap/incremental-marking.cc

@@ -49,6 +49,7 @@ IncrementalMarking::IncrementalMarking(Heap* heap)
       new_generation_observer_(*this, kAllocatedThreshold),
       old_generation_observer_(*this, kAllocatedThreshold),
       marking_state_(nullptr),
+      atomic_marking_state_(nullptr),
       non_atomic_marking_state_(nullptr) {
   SetState(STOPPED);
 }
@@ -471,6 +472,8 @@ void IncrementalMarking::Start(GarbageCollectionReason gc_reason) {
   DCHECK(heap_->gc_state() == Heap::NOT_IN_GC);
   DCHECK(!heap_->isolate()->serializer_enabled());
   marking_state_ = heap_->mark_compact_collector()->marking_state();
+  atomic_marking_state_ =
+      heap_->mark_compact_collector()->atomic_marking_state();
   non_atomic_marking_state_ =
       heap_->mark_compact_collector()->non_atomic_marking_state();
 

src/heap/incremental-marking.h

@@ -60,6 +60,11 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
     return marking_state_;
   }
 
+  MarkCompactCollector::AtomicMarkingState* atomic_marking_state() const {
+    DCHECK_NOT_NULL(atomic_marking_state_);
+    return atomic_marking_state_;
+  }
+
   MarkCompactCollector::NonAtomicMarkingState* non_atomic_marking_state()
       const {
     DCHECK_NOT_NULL(non_atomic_marking_state_);
@@ -69,18 +74,18 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
   void NotifyLeftTrimming(HeapObject* from, HeapObject* to);
 
   V8_INLINE void TransferColor(HeapObject* from, HeapObject* to) {
-    if (marking_state()->IsBlack(to)) {
+    if (atomic_marking_state()->IsBlack(to)) {
       DCHECK(black_allocation());
       return;
     }
 
-    DCHECK(marking_state()->IsWhite(to));
-    if (marking_state()->IsGrey(from)) {
-      bool success = marking_state()->WhiteToGrey(to);
+    DCHECK(atomic_marking_state()->IsWhite(to));
+    if (atomic_marking_state()->IsGrey(from)) {
+      bool success = atomic_marking_state()->WhiteToGrey(to);
       DCHECK(success);
       USE(success);
-    } else if (marking_state()->IsBlack(from)) {
-      bool success = marking_state()->WhiteToBlack(to);
+    } else if (atomic_marking_state()->IsBlack(from)) {
+      bool success = atomic_marking_state()->WhiteToBlack(to);
       DCHECK(success);
       USE(success);
     }
@@ -352,6 +357,7 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
   Observer old_generation_observer_;
 
   MarkCompactCollector::MarkingState* marking_state_;
+  MarkCompactCollector::AtomicMarkingState* atomic_marking_state_;
   MarkCompactCollector::NonAtomicMarkingState* non_atomic_marking_state_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);

src/heap/mark-compact.cc

@@ -1568,7 +1568,7 @@ class YoungGenerationMigrationObserver final : public MigrationObserver {
     // Migrate color to old generation marking in case the object survived young
     // generation garbage collection.
     if (heap_->incremental_marking()->IsMarking()) {
-      DCHECK(mark_compact_collector_->marking_state()->IsWhite(dst));
+      DCHECK(mark_compact_collector_->atomic_marking_state()->IsWhite(dst));
       heap_->incremental_marking()->TransferColor(src, dst);
     }
   }

src/heap/mark-compact.h

@@ -486,6 +486,7 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
   using MarkingState = MajorNonAtomicMarkingState;
 #endif
   using NonAtomicMarkingState = MajorNonAtomicMarkingState;
+  using AtomicMarkingState = MajorMarkingState;
 
   static const int kMainThread = 0;
   // Wrapper for the shared and bailout worklists.
@@ -674,6 +675,8 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
 
   MarkingState* marking_state() { return &marking_state_; }
 
+  AtomicMarkingState* atomic_marking_state() { return &atomic_marking_state_; }
+
   NonAtomicMarkingState* non_atomic_marking_state() {
     return &non_atomic_marking_state_;
   }
@@ -948,6 +951,7 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
   Sweeper sweeper_;
 
   MarkingState marking_state_;
+  AtomicMarkingState atomic_marking_state_;
   NonAtomicMarkingState non_atomic_marking_state_;
 
   friend class FullEvacuator;